diff --git a/lib/calculate.h b/lib/calculate.h
index c33e37fd3b7..470000f95ad 100644
--- a/lib/calculate.h
+++ b/lib/calculate.h
@@ -60,12 +60,16 @@ R calculate(const std::string& s, const T& x, const T& y, bool* error = nullptr)
     constexpr MathLib::bigint maxBitsSignedShift = maxBitsShift - 1;
     switch (MathLib::encodeMultiChar(s)) {
     case '+':
+    case '+=':
         return wrap(x + y);
     case '-':
+    case '-=':
         return wrap(x - y);
     case '*':
+    case '*=':
         return wrap(x * y);
     case '/':
+    case '/=':
         if (isZero(y) || (std::is_signed<T>{} && y < 0)) {
             if (error)
                 *error = true;
@@ -73,6 +77,7 @@ R calculate(const std::string& s, const T& x, const T& y, bool* error = nullptr)
         }
         return wrap(x / y);
     case '%':
+    case '%=':
         if (isZero(MathLib::bigint(y)) || (std::is_signed<T>{} && MathLib::bigint(y) < 0)) {
             if (error)
                 *error = true;
@@ -80,16 +85,20 @@ R calculate(const std::string& s, const T& x, const T& y, bool* error = nullptr)
         }
         return wrap(MathLib::bigint(x) % MathLib::bigint(y));
     case '&':
+    case '&=':
         return wrap(MathLib::bigint(x) & MathLib::bigint(y));
     case '|':
+    case '|=':
         return wrap(MathLib::bigint(x) | MathLib::bigint(y));
     case '^':
+    case '^=':
         return wrap(MathLib::bigint(x) ^ MathLib::bigint(y));
     case '>':
         return wrap(x > y);
     case '<':
         return wrap(x < y);
     case '<<':
+    case '<<=':
         if (y >= maxBitsSignedShift || y < 0 || x < 0) {
             if (error)
                 *error = true;
@@ -97,6 +106,7 @@ R calculate(const std::string& s, const T& x, const T& y, bool* error = nullptr)
         }
         return wrap(MathLib::bigint(x) << MathLib::bigint(y));
     case '>>':
+    case '>>=':
         if (y >= maxBitsSignedShift || y < 0 || x < 0) {
             if (error)
                 *error = true;
diff --git a/lib/vf_settokenvalue.cpp b/lib/vf_settokenvalue.cpp
index e7b715ab36b..2e5b229c0a7 100644
--- a/lib/vf_settokenvalue.cpp
+++ b/lib/vf_settokenvalue.cpp
@@ -486,7 +486,7 @@ namespace ValueFlow
         }
 
         // Calculations..
-        else if ((parent->isArithmeticalOp() || parent->isComparisonOp() || (parent->tokType() == Token::eBitOp) ||
+        else if ((parent->isArithmeticalOp() || parent->isComparisonOp() || (parent->tokType() == Token::eBitOp) || (Token::Match(parent, "%assign%") && parent->str().size() > 1) ||
                   (parent->tokType() == Token::eLogicalOp)) &&
                  parent->astOperand1() && parent->astOperand2()) {
 
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index b8496c863d5..cfb64b0f121 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -1403,6 +1403,12 @@ class TestValueFlow : public TestFixture {
                 "}\n";
         ASSERT_NO_THROW(tokenValues(code, "<=>"));
 
+        code  = "int f() {\n" // #15184
+                "    int i = -1;\n"
+                "    return 1 / (i += 1);\n"
+                "}\n";
+        ASSERT_EQUALS(true, testKnownValueOfTok(code, "+=", 0));
+
         // Comparison of string
         values = removeImpossible(tokenValues("f(\"xyz\" == \"xyz\");\n", "==")); // implementation defined
         ASSERT_EQUALS(0U, values.size()); // <- no value